Mercaptans commonly are employed in suspension polymerization systems to act as molecular weight regulators or modifiers. While effective, these have, at times, exhibited some objectionable characteristics such as residual mercaptan odor in the polymeric product. Possible volatilization of lower molecular weight species may be objectionable in some environments, either due to the odor, or to corrosion or discoloration of metal where the mercaptan modified polymer is in contact with a metal in the further presence of moisture.
It would be desirable to be able to produce polymeric products that exhibit satisfactory physical properties, but employing molecular weight modifiers that either would be free of objectionable residual odor, or would have minimal odor of other than a sulfur derived type, and for many applications modified rubbers not containing sulfur would be highly desired.